1. Field of the Invention
The present invention relates to the technical field of touch panels and, more particularly, to a touch panel with a singly-layer low-complexity transparent electrode pattern and the sensing method therefor.
2. Description of Related Art
The principle of touch panels is based on different sensing manners to detect a voltage, current, acoustic wave, or infrared to thereby detect the coordinates of touch points on a screen where a finger or external object touches. For example, a resistive touch panel uses a potential difference between the upper and lower electrodes to compute the position of a touched point for detecting the location of the touch point, and a capacitive touch panel uses a capacitance change generated in an electrostatic combination of the arranged transparent electrodes with a human body to generate a current or voltage for detecting touch coordinates.
FIG. 1 is a schematic view of a typical two-layer transparent electrode structure. In FIG. 1, the transparent electrodes are arranged in X-axis direction and Y-axis direction, and the two layers of the transparent electrodes are separated by a glass layer or a plastic layer. The advantage of the structure shown in FIG. 1 is that two or more touch points can be sensed and there is a good linearity. However, the disadvantage is that the material cost is high and the manufacturing process is complicated.
To overcome the high cost problem, a direct solution is to use a single-layer transparent electrode structure. FIG. 2 is a schematic view of a typical single-layer transparent electrode structure. As shown in FIG. 2, the structure is a single sensing layer of triangle pattern. A touch screen with the single-layer transparent electrode structure has the advantages of saving the material cost and simplifying the manufacturing process. Such a structure can carry out the two-dimensional coordinate recognition. However, when detecting two touch points, particularly two touch points on the same axial line, the two touch points may be erroneously determined to be one single touch point.
To overcome this, another typical single-layer transparent electrode structure is schematically shown in FIG. 3. The structure of FIG. 3 can carry out a real multi-touch detection while saving the material cost and simplifying the manufacturing process. However, the traces 31 in the structure of FIG. 3 are complicated, and the linearity is poor because the traces 31 occupy a significant amount of area. Taking a 4.3 inch multi-touch screen designed with a single-layer transparent electrode structure as an example, it needs approximately 12 sensing points in a horizontal direction and 20 sensing points in a vertical direction. In this case, there are 240 sensing points required in total for carrying out a multi-touch operation on the 4.3 inch multi-touch screen with a sufficient precision. Since every sensing point needs one sensing trace as a connection to the touch IC, there are 240 traces required for the 240 sensing points, resulting in that the traces arrangement is complicated and thus the pattern design is not easy.
Therefore, it is desirable to provide an improved single-layer transparent electrode structure to mitigate and/or obviate the afore-mentioned problems.